diff options
Diffstat (limited to 'eval.c')
| -rw-r--r-- | eval.c | 35 |
1 files changed, 35 insertions, 0 deletions
@@ -4074,6 +4074,39 @@ static val expand_right(val gen_fun, val init_val) return make_lazy_cons(func_f1(cons(pair, gen_fun), expand_right_fun)); } +static val expand_left(val gen_fun, val init_val) +{ + val out = nil; + + for (;;) { + val pair = funcall1(gen_fun, init_val); + if (pair) { + cons_bind (elem, next, pair); + init_val = next; + out = cons(elem, out); + continue; + } + + return out; + } +} + +static val nexpand_left(val gen_fun, val init_val) +{ + val out = nil; + + for (;;) { + val pair = funcall1(gen_fun, init_val); + if (pair) { + init_val = cdr(pair); + out = rplacd(pair, out); + continue; + } + + return out; + } +} + static val repeat_infinite_func(val env, val lcons) { if (!car(env)) @@ -5169,6 +5202,8 @@ void eval_init(void) reg_fun(intern(lit("giterate"), user_package), func_n3o(giterate, 2)); reg_fun(intern(lit("ginterate"), user_package), func_n3o(ginterate, 2)); reg_fun(intern(lit("expand-right"), user_package), func_n2(expand_right)); + reg_fun(intern(lit("expand-left"), user_package), func_n2(expand_left)); + reg_fun(intern(lit("nexpand-left"), user_package), func_n2(nexpand_left)); reg_fun(intern(lit("repeat"), user_package), func_n2o(repeat, 1)); reg_fun(intern(lit("pad"), user_package), func_n3o(pad, 1)); reg_fun(intern(lit("weave"), user_package), func_n0v(weavev)); |